zfstream is a small C++ library which provides an abstraction API for reading and writing compressed and non-compressed files using the same API. It supports libz and libbz2 compression schemes and is based upon the gzstream class written by Deepak Bandyopadhyay and Lutz Kettner. The library is trivial to use and provides client applications with a unified interface for reading and writing files without having to know whether they are compressed or not. This library provides, for example, the client-transparent compression support in libs11n. As far as external dependencies go: it relies on the STL and one or both of libz and/or libbzip2.

License: GNU Lesser/Library General Public License (LGPL)

You can download the sources here:

Filename Size (bytes) Date (Y.M.D)
libs11n_zfstream-2004.12.02.tar.gz 11005 2009.07.27

Code sample:

#include <s11n.net/zfstream/zfstream.hpp>


//////////////////// Input stream:
std::auto_ptr<std::istream> istr =
      zfstream::get_istream( "/path/to/file" );
if( ! istr.get() ) { ... error ... }

// istr might be compressed or might not - we don't care.

//////////////////// Output stream:
// For writing compressed files, we register a preference/policy
// with the library (the default policy is not to compress streams):
zfstream::compression_policy( zfstream::ZLibCompression );
std::auto_ptr<std::ostream> ostr =
     zfstream::get_ostream( "/path/to/file" );
if( ! ostr.get() ) { ... error ... }

// We can now write to ostr using the standard ostream API, without
// caring about whether it's compressed or not.

Compiling and linking client code

When compiling, add the top-level includes path under which you install zfstream to your compiler's INCLUDES option. e.g., if you install under /opt then add -I/opt/include to your INCLUDES and in your client code to #include <s11n.net/zfstream/zfstream.hpp>.

To link your client code, simply link against libs11n_zfstream, normally by passing, for example, -L/opt/lib -ls11n_zfstream. You may also need to link against libz and/or libbz2 - zfstream requires at least one of these in order to be functional.